We propose to study the factors responsible for the control of phospholipid metabolism in two model systems for mammalian cells. In these model systems phosphatide turnover can be stimulated by manipulation of the incubation conditions. The systems to be studied are surviving thyroid slices in which P32 incorporation into lipids can be stimulated by incubation with TSH and Ehrlich ascites cells in suspension culture in which calf serum in the incubation medium stimulates phosphatide turnover. In these systems the detailed biochemical steps of lipid synthesis are investigated under stimulation and at rest to determine control points in the biosynthetic sequences. BIBLIOGRAPHIC REFERENCES: Schneider, Peter B. Activation of Bovine Liver Glycerokinase by Ethanol, Biochim Biophys Acta 397: 110-116, 1975.